The invention can be used for investigating viscoelastic properties of various substances, such as polymers within a wide range of infralow frequencies. Besides the analyzer can be used as a differential vector resolver of harmonic oscillations in various analogue computers.
There exist various infralow frequency transfer function analyzers. One existing infralow frequency transfer function analyzer uses an infralow frequency generator, multipliers and integrators.
A disadvantage of this type of infralow frequency transfer function analyzer is that it depends for its operation on integrating the product of disturbance amplitude by the response of the member under investigation to the disturbance during the period of the disturbance signal, which makes the analysis at low frequencies a very lengthy process.
For example, at frequencies of the order of 10.sup.-.sup.6 Hz the minimum measurement time would be 11 days. Obviously, apart from a considerable waste of time, it is hardly feasible to insure the required reliability and accuracy of measurements.
In the first place, this is due to the difficulties in meeting the requirements to the drift of the integrators, because of which reliable measurements cannot be made at frequencies below 10.sup.-.sup.5 Hz.
Besides, two multipliers and two integrators have to be used for the analysis of one signal and the measurement results require mathematical processing for determining an amplitude-frequency and a phase-frequency characteristic of the controlled member.
There also exists a transfer function analyzer comprising an electromechanical infralow frequency generator, a rotary transformer mechanically coupled to the output shaft of the electromechanical infralow frequency generator, a modulator connected to the rotary transformer and an indicating instrument.
A disadvantage of such type of transfer function analyzers is that they too require much time for measuring the characteristics of the signal being analyzed at infralow frequencies.